Editing Packet forwarding (section)

==Decisions==
At nodes where multiple outgoing links are available, the choice of which, all, or any to use for forwarding a given packet requires a decision-making process that, while simple in concept, is sometimes bewilderingly complex. Since a forwarding decision must be made for every packet handled by a node, the total time required for this can become a major limiting factor in overall network performance. Much of the design effort of high-speed [[Router (computing)|routers]] and [[network switch|switches]] has been focused on making rapid forwarding decisions for large numbers of packets.

The forwarding decision is generally made using one of two processes: [[routing]], which uses information encoded in a device's address to infer its location on the network, or [[bridging (networking)|bridging]], which makes no assumptions about where addresses are located and depends heavily on broadcasting to locate unknown addresses. The heavy overhead of broadcasting has led to the dominance of routing in large networks, particularly the [[Internet]]; bridging is largely relegated to small networks where the overhead of broadcasting is tolerable. However, since large networks are usually composed of many smaller networks linked together, it would be inaccurate to state that bridging has no use on the Internet; rather, its use is localized.